Exposure apparatus and device manufacturing method

ABSTRACT

An exposure apparatus which prevents damages due to leaked out liquid from expanding and can maintain exposure accuracy and measuring accuracy. The exposure apparatus includes first and second stages (ST 1 , ST 2 ) which can independently move within an XY-plane on an image plane side of a projection optical system (PL); a drive mechanism (SD) which moves the first stage and the second stage together with the stage being close to or in contact with each other; a liquid immersion mechanism ( 1 ) which forms a liquid immersion area on an upper plane of at least one of the stages of the first stage and the second stage; and a detecting device ( 60 ) which detects liquid leaked out from between the first stage and the second stage.

TECHNICAL FIELD

The present invention relates to an exposure apparatus that exposes asubstrate via an optical system and to a device manufacturing method.

The present application claims priority to Japanese Patent ApplicationNo. 2004-301639, filed on Oct. 15, 2004, and its content is incorporatedherein by reference.

BACKGROUND ART

In the photolithography process, which is one of the processes formanufacturing micro-devices such as semiconductor devices or liquidcrystal display devices, an exposure apparatus that projects a patternformed on a mask onto a photosensitive substrate is used. Such anexposure apparatus has a mask stage that supports a mask and a substratestage that supports a substrate and, while successively moving the maskstage and the substrate stage, projects an image of the pattern of themask onto the substrate via a projection optical system. By the way,some of such exposure apparatuses include two stages that are movableindependently of each other on the image plane side of the projectionoptical system. Further, in manufacturing micro-devices, miniaturizationof the pattern formed on a substrate is required in order to make suchmicro-devices high-density ones. To address this requirement, it isdesired that the exposure apparatus have a still higher resolution. As ameans for realizing such a still higher resolution, such a liquidimmersion exposure apparatus as disclosed in the patent document 1,below, in which the space between the projection optical system and thesubstrate is filled with a liquid to form a liquid immersion region, andan exposure process on the substrate is performed via the liquid of theliquid immersion region. Patent Document 1: International Publication WO99149504 pamphlet.

DISCLOSURE OF THE INVENTION

Problem to be Solved By the Invention

When the liquid leaks out, the environment (humidity etc.) in which theexposure apparatus is placed changes due to the liquid having leakedout, and thus there occurs a possibility that the exposure accuracy andthe measurement accuracy are adversely affected. Further, if the liquidhaving leaked out is left as it is, various devices constituting theexposure apparatus may, for example, break down or rust, spreading thedamage.

The present invention has been made in consideration of such situations,and its object is to provide an exposure apparatus which prevents thedamage due to the liquid having leaked out from sealing and by which theexposure accuracy and the measurement accuracy can be min ed and toprovide a device m in method.

Means for Solving Problem

In accordance with a first aspect of the present invention, there isprovided an exposure apparatus that exposes a substrate via a projectionoptical system, comprising: a first stage and a second stage that aremovable, on the image plane side of the projection optical system,independently of each other in a two-dimensional plane substantiallyparallel to the image plane, a driving mechanism that moves the firststage and the second stage together within a predetermined regionincluding the position directly beneath the projection optical systemwith the first stage and the second stage being close to or in contactwith each other, a liquid immersion mechanism that forms a liquidimmersion region of a liquid on the upper surface of at least one of thestages of the first stage and the second stage, a controller that bymoving the first stage and the second stage together, moves the liquidimmersion region between the upper surface of the first stage and theupper surface of the second stage with the liquid being retained betweenthe projection optical system and the upper surface of at least one ofthe stages, and a detecting device that detects the liquid having leakedfrom between the first stage and the second stage when moving the liquidimmersion region from the upper surface of one of the stages of thefirst stage and the second stage to the upper surface of the otherstage.

In accordance with the first aspect of the present invention, there isprovided the detecting device that detects the liquid having leaked frombetween the first stage and the second stage when the liquid immersionregion of the liquid has been moved between the upper surface of thefirst stage and the upper surface of the second stage, and thus when thedetecting device has detected the liquid, an appropriate action toprevent the damage due to the liquid having leaked from spreading can bepromptly taken. Thus, the good exposure accuracy and the goodmeasurement accuracy can be maintained.

In accordance with a second aspect of the present invention, there isprovided a device manufacturing method that uses an exposure apparatus(EX) of the above-described mode.

In accordance with the second aspect of the present invention, since theexposure process and the measurement process can be performed well,devices having a desired performance can be manufactured.

Effect of the Invention

In accordance with the present invention, since the damage due to theliquid having leaked out can be prevented from spreading, the exposureaccuracy and the measurement accuracy can be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an exposure apparatus inaccordance with a first embodiment.

FIG. 2 is a plan view of a substrate stage and a measurement stage, asviewed from above.

FIG. 3A is a drawing for illustrating the operations of the substratestage and the measurement stage.

FIG. 3B is a drawing for illustrating the operations of the substratestage and the measurement stage.

FIG. 4A is a drawing for illustrating the operations of the substratestage and the measurement stage.

FIG. 4B is a drawing for illustrating the operations of the substratestage and the measurement stage.

FIG. 5 is a drawing for illustrating a condition in which a detectingdevice is detecting a liquid.

FIG; 6 is an enlarged view of a main portion of an exposure apparatus inaccordance with a second embodiment.

FIG. 7 is a schematic diagram showing an exposure apparatus inaccordance with a third embodiment.

FIG. 8 is a flowchart showing an example of a micro-device manufacturingprocess.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, although embodiments of the present invention will bedescribed referring to the drawings, the present invention is notlimited to those embodiments.

First Embodiment

FIG. 1 is a schematic diagram showing an exposure apparatus inaccordance with a first embodiment. In FIG. 1, exposure apparatus EXincludes mask stage MST that is movable while holding mask M, withsubstrate stage ST1 that is movable while holding substrate P, withmeasurement stage ST2 that is movable while measuring devices related tothe exposure process being mounted thereon, with illumination opticalsystem IL that illuminates mask M held by mask stage MST with exposurelight EL, with projection optical system PL that projects a patternimage of mask M illuminated with exposure light EL onto substrate P heldby substrate stage ST1, and with controller CONT that controls theoverall operation of exposure apparatus EX. Substrate stage ST1 andmeasure stage ST2 are each movably supported on base member BP and aremovable independently of each other. On undersurface U1 of substratestage ST1 are provided gas bearings 41 for supporting substrate stageST1 in a non-contact manner relative to upper surface BT of base memberBP. Similarly, also on undersurface U2 of measurement stage ST2 areprovided gas bearings 42 for supporting measurement stage ST2 in anon-contact manner relative to upper surface BT of base member BP.Substrate stage ST1 and measurement stage ST2 are movable respectivelyon the image plane side of the projection optical system PL,independently of each other in a two-dimensional plane (in the XY-plane)substantially parallel to the image plane.

Exposure apparatus EX of this embodiment is a liquid immersion exposureapparatus to which a liquid immersion method is applied, with theexposure wavelength being shortened in effect, to improve the resolutionand, at the same time, to widen the depth of focus. Further, exposureapparatus EX includes liquid immersion mechanism 1 for forming liquidLQ's liquid immersion region LR on the image plane side of projectionoptical system PL. Liquid immersion mechanism 1 includes nozzle member70 that is provided on the image plane side vicinity of projectionoptical system PL and has supply ports 12 for supplying liquid LQ andrecovery ports 22 for recovering liquid LQ, with liquid supply mechanism10 that supplies liquid LQ to the image plane side of projection opticalsystem PL via supply ports 12 provided to nozzle member 70, and withliquid recovery mechanism 20 that recovers liquid LQ on the image planeside of projection optical system PL via recovery ports 22 provided tonozzle member 70. Nozzle member 70 is formed in a ring-shaped manner soas to surround the end portion of projection optical system PL on theimage plane side. At least while transferring the pattern image of maskM onto substrate P, exposure apparatus EX locally forms, by liquid LQhaving been supplied from liquid supply mechanism 10, liquid LQ's liquidimmersion region LR that is larger than projection area AR of projectionoptical system PL and is smaller than substrate P on a portion ofsubstrate P that includes projection area AR. More specifically,exposure apparatus EX adopts a local liquid immersion system in whichthe optical path space between first optical element LS1 located closestto the image plane of projection optical system PL and a portion of thesurface of substrate P placed on the image plane side of projectionoptical system PL is filled with liquid LQ and by irradiating, vialiquid LQ between projection optical system PL and substrate P and viaprojection optical system PL, exposure light EL having passed throughmask M onto substrate P, projects the pattern of mask M onto substrate Pto expose substrate P.

The embodiment will be described by assuming, as an example, a casewhere as exposure apparatus EX, a scan type exposure apparatus (theso-called scanning stepper) in which while synchronously moving mask Mand substrate P in their respective scanning directions directiondifferent from each other (diverse directions), the pattern formed onmask M is exposed onto substrate P is used. In the followingdescription, it is assumed that the synchronous movement direction(scanning direction), in a horizontal plane, of mask M and substrate Pis referred to as the X-axis direction, that the direction, in thehorizontal plane, perpendicular to the X-axis direction is referred toas the Y-axis direction (non-scanning direction), and that the directionthat is perpendicular to the X-axis direction and the Y-axis directionand coincides with optical axis AX of projection optical system PL isreferred to as the Z-axis direction. Further, it is assumed that thedirection around the X-axis, the direction around the Y-axis, and thedirection around the Z-axis are respectively referred to as theθX-direction, the θY-direction, and the θZ-direction. It should be notedthat a “substrate” referred to herein comprehends a base material, e.g.,a semiconductor wafer, over which a photosensitive material (resist) isapplied, and a “mask” comprehends a reticle on which a device pattern tobe reduction-projected onto the substrate is formed.

By opting driving mechanism SD that includes linear motors etc,substrate stage ST1 and measurement stage ST2 are movable, respectively.By controlling driving mechanism SD, controller CONT can move substratestage ST1 and measurement stage ST2 together, in the XY-plane, within apredetermined region including the position directly beneath projectionoptical system PL in a state that substrate stage ST1 and measurementstage ST2 are close to or in contact with each other. By movingsubstrate stage ST1 and measurement stage ST2 together, controller CONTcan move liquid immersion region LR between upper surface F1 ofsubstrate stage ST1 and upper surface F2 of measurement stage ST2 in astate that liquid LQ is retained between projection optical system PLand at least one of upper surface F1 of substrate stage ST1 and uppersurface F2 of measurement stage ST2.

In the embodiment, on the upper portion of the side face of substratestage ST1 is provided overhang portion H1 that protrudes outwardly fromthe center portion of upper surface F1 of substrate stage ST1. The uppersurface of overhang portion H1 is also a portion of upper surface F1 ofsubstrate stage ST1. Similarly, on the upper portion of the side face ofmeasurement stage ST2 is provided overhang portion H2 that protrudesoutwardly from the center portion of upper surface F2 of measurementstage ST2. The upper surface of overhang portion H2 is also a portion ofupper surface F2 of measurement stage ST2. When, for example, liquidimmersion region LR being moved from one of the stages to the otherstage, the +Y side region of upper surface F1 of substrate stage ST1 andthe −Y side region of upper surface F2 of measurement stage ST2 comeclose to or into contact with each other.

Here, the “state that substrate stage ST1 and measurement stage ST2 areclose to each other” means a state in which, when liquid LQ betweenupper surface F1 of substrate stage ST1 and upper surface F2 ofmeasurement stage ST2 being moved, substrate stage ST1 and measurementstage ST2 are close to each other to such a degree that liquid LQ doesnot leak out from between substrate stage ST1 and measurement stage ST2.The allowable value of the space between both stages ST1 and ST2 dependsupon, e.g., the materials, surface treatments of both stages, the kindof liquid LQ or the like.

Further, exposure apparatus EX includes detecting device 60 that detectsliquid LQ having leaked from between substrate stage ST1 and measurementstage ST2 when liquid immersion region LR from upper surface F1 (F2) ofone of the stages of substrate stage ST1 and measurement stage ST2 toupper surface F2 (F1) of the other stage being moved. As describedabove, substrate stage ST1 and measurement stage ST2 are controlled suchthat their relative positional relationship is minimal so as to preventliquid LQ from leaking, and they are moved together in a state that theyare close to or in contact with each other. However, even if liquid LQhas leaked out, detecting device 60 is capable of detecting the liquidLQ having leaked.

Detecting device 60 includes light projecting portion 61 that emitsdetecting light La and with light receiving portion 62 that is disposedin a predetermined position relative to detecting light La. Lightprojecting portion 61 is provided on second side surface 12 ofmeasurement stage ST2. On the other hand, light receiving portion 62 isprovided on first side surface T1 of substrate stage ST1. First sidesurface T1 of substrate stage ST1 constitutes a region under overhangportion H1 and is a surface facing toward the +Y side. Further, secondside surface T2 of measurement stage ST2 constitutes a region underoverhang portion H2 and is a surface facing toward the −Y side. Thus,first side surface T1 of substrate stage ST1 and second side T2 ofmeasurement stage ST2 face each other. Further, also on side face 42T ofgas bearing 42, which supports measurement stage ST2 in a non-contactmanner relative to base member BP, is provided light projecting portion63 that emits detecting light Lb. On side face 41T of gas bearing 41,which supports substrate stage ST1 in a non-contact manner relative tobase member BP, is provided light receiving portion 64 that correspondsto light projecting portion 63. Side face 41T of gas bearing 41 is asurface facing toward the +Y side; side face 42T of gas bearing 42 is asurface facing toward the −Y side; side face 41T of gas bearing 41 andside face 42T of gas bearing 42 face each other.

Substrate stage ST1 and measurement stage ST2 include overhang portionH1 and overhang portion H2, respectively. Thus, even when upper surfaceF1 of substrate stage ST1 and upper surface F2 of measurement stage ST2are made close to or in contact with each other, second side surface T2,on which light projecting portion 61 is provided, and first side surfaceT1, on which light receiving portion 62 is provided, are mutuallyseparated by a predetermined distance, and, at the same time, side face42T, on which light projecting portion 63 is provided, and side face41T, on which light receiving portion 64 is provided, are mutuallyseparated by a predetermined distance. In other words, when uppersurface F1 of substrate stage ST1 and upper surface F2 of measurementstage ST2 are made close to or in contact with each other, a space isformed under the portion where upper surface F1 and upper surface F2 areclose to (or in contact with) each other.

It should be noted that it may, of course, be configured such that lightprojecting portion 61 is provided on substrate stage ST1, and lightreceiving portion 62 is provided on measurement stage ST2. Similarly, ofcourse, it may also be configured such that light projecting portion 63is provided on gas bearing 41, and light receiving portion 64 isprovided on gas bearing 42.

Illumination optical system IL includes an exposure light source, anoptical integrator for uniforming the illuminance of the light fluxemitted from the exposure light source, a condenser lens for condensingexposure light EL from the optical inflator, a relay lens system, afield stop for setting an illumination area formed by exposure light ELon mask M, etc. A specified illumination area on mask M is illuminated,by illumination optical system IL, with exposure light EL having auniform illuminance distribution. As exposure light EL emitted fromillumination optical system IL, for example, a bright line (g-line,h-line, i-line) emitted from a mercury lamp, a deep ultraviolet light(DUV light) such as a KrF excimer laser light (wavelength of 248 nm), ora vacuum ultraviolet light (VUV light) such as an ArF excimer laserlight (wavelength of 193 nm) or an F₂ excimer laser light (wavelength of157 nm) may be used. In the embodiment, an ArF excimer laser light isused.

In the embodiment, purified or pure water is used as liquid LQ. Purifiedwater can transmit not only an ArF excimer laser light however also, forexample, a bright line (g-line, h-line, or i-line) emitted from amercury lamp and a deep ultraviolet light (DUV light) such as a KrFexcimer laser light (wavelength of 248 mm).

Mask stage MST is movable while holding mask M. Mask stage MST holdsmask M by means of vacuum suction (or electrostatic suction). Byoperating driving mechanism MD which includes a linear motor etc. and iscontrolled by controller CONT, mask stage MST, in the state of holdingmask M, is two-dimensionally movable in a plane perpendicular to opticalaxis AX of projection optical system PL, i.e., in the XY-plane, and isfinely rotatable in the θZ-direction. On mask stage MST is set movingmirror 31. Further, laser interferometer 32 is positioned at a positionfacing moving mirror 31. The two-dimensional position and the rotationangle in the θZ-direction (including the rotation angles in the θX- andθY-directions in some cases) of mask M on mask stage MST are measured bylaser interferometer 32 in real time. The measurement results from laserinterferometer 32 are outputted to controller CONT. By operating drivingmechanism MD based on the measurement results from laser interferometer32, controller CONT performs the position control of mask M held by maskstage MST.

Projection optical system PL is for projecting the pattern image of maskM onto substrate P at a predetermined projection magnification of β andis constituted by a plurality of optical elements, these opticalelements are held by lens barrel PK. In the embodiment, projectionoptical system PL is a reduction system of which projectionmagnification β is, e.g., ¼, ⅕, or ⅛. It should be noted that projectionoptical system PL may also be either a unit magnification system or amagnifying system Among plurality of optical elements constitutingprojection optical system PL, first optical element LS1 located closestto the image plane of projection optical system PL protrudes from lensbarrel PK.

Substrate stage ST1 has substrate holder PH which holds substrate P;substrate stage ST1 can move substrate holder PH in the image plane sideof projection optical system PL. Substrate holder PH holds substrate Pby means of, e.g., vacuum suction. On substrate stage ST1 is provideddepression or recess portion 36, and substrate holder PH for holdingsubstrate P is disposed in depression portion 36. Further, substratestage ST1's upper surface F1 around depression portion 36 is made a flatsurface (flat portion) so that it has a height substantially equal tothat of (constitutes the same plane as) the surface of substrate P heldby substrate holder PH.

By operating driving mechanism SD which includes linear motors etc. andis controlled by controller CONT, substrate stage ST1, in the state ofholding substrate P via substrate holder PH, is two-dimensionallymovable in the XY-plane substantially parallel to the image plane ofprojection optical system PL and is finely rotatable in the θ-Zdirection, on the image plane side of projection optical system PL.Further, substrate stage ST1 is also movable in the Z-axis-direction, inthe θX-direction, and in the θY-direction. Thus, the upper surface of Psupported by substrate stage ST1 is movable in the six-degree-of-freedomdirections, i.e., in the X-axis-direction, in the Y-axis-direction, inthe Z-axis-direction, in the θX-direction, in the θY-direction, and inthe θZ-direction. On the side face of substrate stage ST1 is providedmoving mirror 33. Further, laser interferometer 34 is positioned at aposition facing moving mirror 33. The two-dimensional position and therotation angle of substrate P on substrate stage ST1 are measured bylaser interferometer 34 in real time. In addition, exposure apparatus EXincludes such an oblique-incidence type focus-leveling detection system(not shown) as disclosed in, e.g., Japanese Unexamined PatentPublication Hei 8-37149 that detects the surface position information ofthe surface of substrate P supported by substrate stage ST1. Thefocus-leveling detection system detects the surface position informationof the surface of substrate P(position information in theZ-axis-direction and inclination information in the θX- andθY-directions of substrate P). It is to be noted that as thefocus-leveling detection system, a system that uses an electriccapacitance type sensor may be adopted. The measurement results fromlaser interferometer 34 are outputted to controller CONT. The detectionresults from the focus-leveling detection system are also outputted tocontroller CONT. By operating driving mechanism SD based on thedetection results from the focus-leveling detection system, controllerCONT controls the focus position (Z-position) and inclination angles(θX, θY) of substrate P to adjust the surface of substrate P to theimage plane of projection optical system PL and, at the same time,performs, based on the measurement results from laser interferometer 34,the position control of substrate P in the X-axis-direction, in theY-axis-direction, and in the θ-Z direction.

Measurement stage ST2 is movable on the image plane side of projectionoptical system PL while various kinds of measuring devices (includingmembers for measurement) that perform measurements related to theexposure process being mounted thereon. As those measuring devices,there can be listed such a fiducial mark plate on which a plurality offiducial marks are formed as disclosed in, e.g., Japanese UnexaminedPatent Publication Hei 5-21314, such a uniformity sensor for measuringthe illumination intensity uniformity as disclosed in, e.g., JapaneseUnnamed Patent Publication Sho 57-117238 or for measuring the variationamount of transmissivity of projection optical system PL for exposurelight EL as disclosed in, e.g., Japanese Patent Application PublicationNo. 2001-267239, such an aerial image measuring sensor as disclosed in,e.g., Japanese Patent Application Publication No. 2002-14005, and such adose sensor (illumination intensity sensor) as disclosed in JapaneseUnexamined Patent Publication Hei 11-16816. Uppers sure F2 ofmeasurement stage ST2 is made a flat surface (flat portion) so that itis substantially equal in height to (co-planer with) upper surface F1 ofsubstrate stage ST1.

In the embodiment, corresponding to the performance of the liquidimmersion exposure, in which substrate P is exposed with exposure lightEL via projection optical system PL and liquid LQ, the above-mentioneduniformity sensor, aerial image measuring sensor, dose sensor, etc.,which are used for measurements using exposure light EL, receiveexposure light EL via projection optical system PL and liquid LQ.Further, with respect to each sensor, only a portion of, e.g., itsoptical system may be mounted on measurement stage ST2 or the entiretyof the sensor may be disposed on measurement stage ST2.

By operating driving mechanism SD which includes linear motors etc. andis controlled by controller CONT, measurement stage ST2, in the statethat the measuring devices are mounted thereon, is two-dimensionallymovable in the XY-plane substantially parallel to the image plane ofprojection optical system PL and is finely rotatable in theθZ-direction, on the image plane side of projection optical system PL.Further, measurement stage ST2 is also movable in the Z-axis-direction,in the θX-direction, and in the θY-direction. In other words, as withsubstrate stage ST1, measurement stage ST2 is also movable in thesix-degree-of-freedom directions, i.e., in the X-axis-direction, in theY-axis-direction, in the Z-axis-direction, in the θX-direction, in theθY-direction, and in the θZ direction. On the side face of measurementstage ST2 is provided moving mirror 37. Further, laser interferometer 38is positioned at a position facing moving mirror 37. The two-dimensionalposition and the rotation angle of measurement stage 52 are measured bylaser interferometer 38 in real time.

It should be noted that while, in FIG.1, moving mirror 33 and movingmirror 37 are respectively provided on overhang portion H1 of the stageST1 and overhang portion H2 of the stage ST2, those moving mirrors maybe respectively provided on the side face under the overhang portions.By doing so, even when liquid LQ leaks out from upper surface F1 orupper surface F2, overhang portion H1 or overhang portion H2 can preventliquid LQ from adhering to moving mirror 33 or moving mirror 37.

In the vicinity of the end portion of projection optical system PL isprovided an off-axis type alignment system ALG that detects an alignmentmark on substrate P and fiducial mark on the fiducial mark plate. In thealignment system ALG of the embodiment, there is adopted such an FIA(Field Image Alignment) type system as disclosed in, e.g., JapaneseUnexamined Patent Publication Hei 4-65603, in which a broad-banddetecting light beam which does not expose the photosensitive materialon substrate P is irradiated onto the target mark, the target marks'image imaged, by the reflected lights from the target mark, on the lightreceiving surface and the image of fiducial mark (fiducial mark patternon a fiducial mark plate provided in alignment system ALG), not shown,are imaged by using an image pick-up device (e.g., a CCD), and then byapplying an image processing on the image signals obtained the marks'position is measured.

Further, in the vicinity of mask stage MST are provided a pair of maskalignment systems RAa and RAb, with those mask alignment systems beingmutually separated in the Y-axis-direction by a predetermined distance,each of which constitutes a TTR type alignment system, using a lighthaving the same wavelength as the exposure light, for simultaneouslyobserving via projection optical system PL the alignment marks on mask Mand the corresponding fiducial marks on the fiducial mark plate. In themask alignment system of the embodiment, there is adopted such a VRA(Visual Reticle Alignment) system as disclosed in, e.g., JapaneseUnexamined Patent Publication Hei 7-176468, in which a light isirradiated onto the marks, and by applying an image processing on theimage data of the marks imaged by, e.g., a CCD, the marks' positions aredetected.

Next liquid supply mechanism 10 and liquid recovery mechanism 20 ofliquid immersion mechanism 1 will be described. Liquid supply mechanism10 is for supplying liquid LQ to the image plane side of projectionoptical system PL and includes liquid supply portion 11 capable ofdelivering liquid LQ and with supply pipe 13 of which one end portion isconnected to liquid supply portion 11. The other end portion of supplypipe 13 is connected to nozzle member 70. Inside nozzle member 70 isformed an inner flow path (supply flow path) that connects the other endportion of supply pipe 13 to supply ports 12. Liquid supply portion 11includes a tank that stores liquid LQ, a pressurizing pump, a filterunit that removes foreign particles in liquid LQ, etc. The liquid supplyoperation of liquid supply device 11 is controlled by controller CONT.

Liquid recovery mechanism 20 is for recovering liquid LQ from the imageplane side of projection optical system PL and includes liquid recoveryportion 21 capable of recovering liquid LQ and with recovery pipe 23 ofwhich one end is connected to liquid recovery portion 21. The other endof recovery pipe 23 is connected to nozzle member 70. Inside nozzlemember 70 is formed an inner flow path (recovery flow path) thatconnects the other end portion of recovery pipe 23 to recovery port 22.Liquid recovery portion 21 includes a vacuum system (suction device),e.g., a vacuum pump, a gas-liquid separator that separates the recoveredliquid LQ from gas, a tank that stores the recovered liquid LQ, etc.

Supply ports 12 that supplies liquid LQ and recovery port 22 thatrecovers liquid LQ are formed on undersurface 70A of nozzle member 70.Undersurface 70A of nozzle member 70 is disposed in a position facingthe surface of substrate P, upper surface F1 of the stage ST1, and uppersurface F2 of the stage ST2. Nozzle member 70 is a ring-shaped memberthat is provided so as to surround the side face of first opticalelement LS1. A plurality of supply ports 12 are provided so as tosurround, in undersurface 70A of nozzle member 70, first optical elementLS1 of projection optical system PL (optical axis AX of projectionoptical system PL). Further, recovery port 22 is provided, inundersurface 70A of nozzle member 70, outside supply ports 12 relativeto first optical element LS1 and thus is provided so as to surroundfirst optical element LS1 and supply ports 12.

Finally, by supplying a predetermined amount of liquid LQ onto substrateP by using liquid supply mechanism 10 and by, at the same time,recovering a predetermined amount of liquid LQ on substrate P by usingliquid recovery mechanism 20, controller CONT locally forms on substrateP liquid immersion region LR of liquid LQ. In forming liquid immersionregion LR of liquid LQ, controller CONT operates each of liquid supplyportion 11 and liquid recovery portion 21. When liquid LQ is deliveredfrom liquid supply portion 11 under control of controller CONT, theliquid LQ delivered from liquid supply portion 11 is, after flowingthrough supply pipe 13, supplied, via the supply flow path of nozzlemember 70, from supply ports 12 to the image plane side portion ofprojection optical system PL. Further, when liquid recovery portion 21is driven under control of controller CONT, liquid LQ on the image planeside of projection optical system PL flows, via recovery port 22, intothe recovery flow path of nozzle member 70 and, after flowing throughrecovery pipe 23, is recovered by liquid recovery portion 21.

FIG. 2 is a drawing of substrate stage ST1 and measurement stage ST2, asviewed from above. In FIG. 2, driving mechanism SD for driving substratestage ST1 and measurement stage ST2 includes linear motors 80, 81, 82,83, 84, and 85. Driving mechanism SD includes a pair of Y-axis linearguides 91 and 93 extending in the Y-axis direction. Each of Y-axislinear guides 91 and 93 is disposed such that they are mutuallyseparated, in the X-axis-direction, by a predetermined distance. Each ofY-axis linear guides 91 and 93 is constituted by a magnet unit in whicha permanent magnet group constituted by multiple pairs of an N-pole metand an S-pole magnet disposed at predetermined intervals and alternatelyalong, e.g., the Y-axis on is embedded. On Y-axis linear guide 91, whichis one of the Y-axis linear guides are supported two sliders 90 and 94movably in the Y-axis direction in a non-contact state. Similarly, onY-axis linear guide 93, which is the other one of the Y-axis linearguides, are supported two sliders 92 and 95 movably in theY-axis-direction in a non-contact state. Each of sliders 90, 92, 94, and95 is constituted by a coil unit in which armature coils disposed atintervals along, e.g., the Y-axis direction are embedded. In otherwords, in the embodiment, each of the moving coil type Y-axis linearmotors 82 and 84 is constituted by slider 90 constituted by the coilunit and Y-axis linear guide 91 and by slider 94 constituted by the coilunit and Y-axis linear guide 91, respectively. Similarly, each of themoving coil type Y-axis linear motors 83 and 85 is constituted by slider92 and Y-axis linear guide 93 and by slider 95 and Y-axis linear guide93, respectively.

Slider 90 constituting Y-axis linear motor 82 and slider 92 constitutingY-axis linear motor 83 are respectively fixed to one end portion and theother end portion located in the longitudinal direction of X-axis linearguide 87 extending in the X-axis on Further, slider 94 constitutingY-axis linear motor 84 and slider 95 constituting Y-axis linear motor 85are respectively fixed to one end portion and the other end portionlocated in the longitudinal direction of X-axis linear guide 89extending in the X-axis-direction. Thus, X-axis linear guide 87 can bemoved in the Y-axis direction by Y-axis linear motors 82 and 83; X-axislinear guide 89 can be moved in the Y-axis-direction by Y-axis linearmotors 84 and 85.

Each of X-axis linear guides 87 and 89 is constituted by a coil unit inwhich armature coils disposed at predetermined intervals along, e.g.,the X-axis-direction are embedded. X-axis linear guide 89 is provided,in an inserted state, to an opening portion formed in substrate stageST1. Inside the opening portion of substrate stage ST1 is providedmagnet unit 88 having a permanent magnet group constituted by multiplepairs of an N-pole magnet and an S-pole magnet disposed at predeterminedintervals and alternately along, e.g, the X-axis direction. A movingmagnet type X-axis liner motor 81 that drives substrate stage ST1 in theX-axis-direction is constituted by magnet unit 88 and X-axis linearguide 89. Similarly, X-axis linear guide 87 is provided, in an insertedstate, to an opening portion formed in measurement stage ST2. In theopening portion of measurement stage ST2 is provided magnet unit 86. Amoving magnet type X-axis linear motor 80 that drives measurement ST2 inthe X-axis-direction is constituted by magnet unit 86 and X-axis linearguide 87.

Further, by making the driving forces generated by the pair of Y-axislinear motors 84 and 85 (or 82 and 83) slightly different from eachother, control in the θZ-direction of substrate stage ST1 (ormeasurement stage ST2) can be implemented Further, in the drawing, eachof sure stage ST1 and measurement stage ST2 is illustrated as a singlestage, however, actually, each of the stages includes an XY stage drivenby the Y-axis linear motors and with a Z-tilt stage that is mounted overthe XY stage via a Z-leveling driving mechanism (e.g., voice coilmotors) and is finely moved relative to the XY stage in theZ-axis-direction, in the θX-direction, and in the θY-direction. Further,substrate holder PH (see FIG. 1), which holds substrate P, is supportedby the Z-tilt stage.

In the following, referring to FIGS. 2-4B, there will be describedparallel processing operations using substrate stage ST1 and measurementstage ST2.

As shown in FIG. 2, during a liquid immersion exposure of substrate P,controller CONT makes measurement stage S12 wait at a predeterminedwaiting position where measurement stage ST2 does not collide withsubstrate stage ST1. Further, in the state that substrate stage ST1 andmeasurement stage ST2 are mutually separated, controller CONT performs astep-and-scan type liquid immersion exposure on substrate P supported bysubstrate stage ST1. When substrate P is subjected to a liquid immersionexposure, controller CONT forms liquid immersion region LR of liquid LQon substrate stage ST1 by using liquid immersion mechanism 1.

Upon completion of the liquid immersion exposure on substrate P insubstrate stage ST1, controller CONT moves measurement stage ST2 byusing driving mechanism SD to make measurement stage ST2 come intocontact with or close to substrate stage ST1, as shown in FIG. 3A.

Next, while maintaining the relative positional relationship in theY-axis-direction between substrate stage ST1 and measurement stage ST2,controller CONT moves substrate stage ST1 and measurement stage ST2simultaneously in the-Y direction by using driving mechanism SD. Morespecifically, controller CONT moves substrate stage ST1 and measurementstage ST2 together in the -Y direction within a predetermined regionincluding the position directly beneath projection optical system PL ina state that substrate stage ST1 and measurement stage ST2 are incontact with (or close to) each other.

By moving substrate stage ST1 and measurement stage ST2 together,controller CONT moves liquid immersion region LR of liquid LQ retainedbetween first optical element LS1 of projection optical system PL andsubstrate P, by way of upper surface F1 of substrate stage ST1, to uppersurface F2 of measurement stage S2. In accordance with the movement inthe -Y direction of substrate stage ST1 and measurement stage ST2,liquid LQ's liquid immersion region LR that was formed between firstoptical element LS1 of projection optical system and substrate P movesto the surface of substrate P, to upper surface F1 of substrate stageST1, and to upper surface F2 of measurement stage ST2, in this order. Inthis regard, along the way when liquid immersion region LR of liquid LQmoves from upper surface F1 of substrate stage ST1 to upper surface F2of measurement stage ST2, liquid immersion region LR is disposed suchthat it straddles the boundary region between upper surface F1 ofsubstrate stage ST1 and upper surface F2 of measurement stage ST2, asshown in FIG. 3B.

When, from the state of FIG. 3A, substrate stage ST1 and measurementstage ST2 further move together in the -Y direction by a predetermineddistance, there occurs, as shown in FIG. 4A, the state in which liquidLQ is retained between first optical element LS1 of projection opticalsystem PL and measurement stage ST2. In other words, liquid immersionregion LR of LQ is disposed on upper surface F2 of measurement stageST2.

Next, controller CONT moves substrate stage ST1 to a predeterminedsubstrate exchange position by using driving mechanism SD to exchangesubstrate P and, in parallel to this process, performs predeterminedmeasurement processes using measurement stage ST2, as required. As anexample of such measurement process, there is the baseline measurementof alignment system ALG. Specifically, controller CONT simultaneouslydetects a pair of first fiducial marks on fiducial mark plate FMprovided on measurement stage ST2 and mask alignment marks on mask Mcorresponding to the first fiducial marks by using the above-describedmask alignment systems RAa and RAb and detects the positionalrelationship between the first fiducial marks and the mask alignmentmarks corresponding thereto. Further, by detecting a second fiducialmark on fiducial mark plate FM by use of alignment system ALG,controller CONT detects the positional relationship between thedetection reference position of alignment system ALG and the secondfiducial mark. Further, based upon the detected positional relationshipbetween the above-described first fiducial marks and the mask alignmentmarks corresponding thereto, the detected positional relationshipbetween the detection reference position of alignment system ALG and thesecond fiducial mar, and a known positional relationship between thefirst fiducial marks and the second fiducial mark, controller CONTdetermines the distance between the projection center of the maskpattern formed by projection optical system PL and the detectionreference position of alignment system ALG, i.e., the baseline ofalignment system ALG. FIG. 4B shows the state at this time.

Further, upon completion of the above-described processes on both stagesST1 and ST2, controller CONT, for example, makes measurement stage ST2and substrate stage ST1 come into contact with (or close to) each otherand then moves the stages in the XY-plane in the state that theirrelative positional relationship is maintained to perform alignmentprocesses on the exchanged substrate P. In this regard, a plurality ofshot areas are set on substrate P. Alignment marks associated with eachof the plurality of shot areas are provided. Controller CONT detects thealignment marks on the exchanged substrate P by using alignment systemALG and calculates the position coordinates of each of the plurality ofshot areas set on substrate P relative to the detection referenceposition of alignment system ALG.

Thereafter, in reverse to the former process, by moving substrate stageST1 and measurement stage ST2 together in the +Y direction whilemaintaining the relative positional relationship in the Y-axis-directionbetween both stages ST1 and ST2, controller CONT moves substrate stageST1 (substrate P) under projection optical system PL and then movesmeasurement stage ST2 to a predetermined position. By this, liquidimmersion region LR is disposed on upper surface F1 of substrate stageST1. Also along the way when liquid immersion region LR of liquid LQ ismoved from upper surface of measurement stage ST2 to upper surface F1 ofsubstrate stage ST1, liquid immersion region LR is disposed such that itstraddles the boundary region between upper surface F1 of substratestage ST1 and upper surface F2 of measurement stage ST2.

Thereafter, controller CONT performs a step-and-scan type liquidimmersion exposure process on substrate P to sequentially transfer thepattern of mask M onto each of the plurality of shot areas on substrateP. It is to be noted that the movement (position) of substrate stage ST1for the purpose of exposing each shot area on substrate P is controlledbased upon the position coordinates of the plurality of shot areas onsubstrate P obtained through the above described substrate alignment andupon the baseline measured just before.

It is to be noted that the measurement operation should not be limitedto the above described baseline measurement; it may also be configuredsuch that an illumination intensity measurement, an illuminationintensity uniformity measurement, an aerial image measurement, etc. areperformed in parallel to, e.g., the substrate exchange process, by usingmeasurement stage ST2, and such measurements are reflected in theexposure of substrate P performed thereafter, by performing, e.g., acalibration process of projection optical system PL based upon themeasurement results from such measurements.

Further, in the above-described description, the alignment process onthe exchanged substrate P is performed in the state that substrate stageST1 and measurement stage ST2 are in contact with (or close to) eachother, however it may also be configured such that upon completion ofthe alignment process on exchanged substrate P, substrate stage ST1 andmeasurement stage ST2 are made to come into contact with (close to) eachother to move liquid immersion region LR.

Since, in the embodiment, liquid immersion region LR of liquid LQ can bemoved between upper surface F1 of substrate stage ST1 and upper surfaceF2 of measurement stage ST2 without performing such processes as fullrecovery of liquid LQ and re-supply of liquid LQ, the time between thecompletion of the exposure operation in substrate stage ST1 and thebeginning of the measurement operation in measurement stage ST2 and thetime between the measurement completion in measurement stage ST2 and thebeginning of the exposure operation in substrate stage ST1 areshortened, and thus the throughput can be improved. Further, sinceliquid LQ always exists on the image plane side of projection opticalsystem PL, generation of an adhesion trace (so-called water mark) can beeffectively prevented.

As described above, along the way when liquid immersion region LR ofliquid LQ is moved from upper surface F1 of substrate stage ST1 to uppersurface F2 of measurement stage ST2 or along the way when the liquid ismoved from upper surface F2 of measurement stage ST2 to upper surface F1of substrate stage ST1, there arises the state that liquid immersionregion LR is disposed such that it straddles the boundary region betweenupper surface F1 of substrate stage ST1 and upper surface F2 ofmeasurement stage ST2.

FIG. 5 is a drawing showing the state in which liquid immersion regionLR straddles the boundary region between upper spice F1 of substratestage ST1 and upper surface F2 of measurement stage ST2. In this state,liquid LQ of liquid immersion region LR may leak from between substratestage ST1 and measurement stage ST2. When liquid LQ leaks from gap Gbetween upper surface F1 of substrate stage ST1 and upper surface F2 ofmeasurement stage ST2, the liquid LQ having leaked drops from the uppersurfaces F1 and F2 by the action of gravitation. Detecting device 60detects in a non-contact manner the liquid LQ having leaked.

Substrate stage ST1 and measurement stage ST2 have overhang portion H1and overhang portion H2, respectively. Thus, even when upper surface F1of substrate stage ST1 and upper surface F2 of measurement stage ST2 aremade to come close to or into contact with each other, it is configuredsuch that space H is formed under the portion where upper surface F1 andupper surface F2 are close to or in contact with each other, i.e., undergap G. Thus, liquid LQ having leaked from gap G drops, after passingthrough space H, onto base member BP. Further, even when upper surfaceF1 of substrate stage ST1 and upper surface F2 of measurement stage ST2are made to come close to or into contact with each other, the opticalpath spaces of detecting light La and detecting light Lb are secured byspace H. Here, detecting light La emitted from light projecting portion61 and detecting light Lb emitted from light projecting portion 63proceed substantially in parallel to the XY-plane. In particular,detecting light Lb emitted from light projecting portion 63 proceeds, inthe vicinity of base member BP, substantially in parallel to uppersurface BT of base member BP.

Based on the light reception results from light receiving portion 62,detecting device 60 detects whether there is liquid LQ in space H. Morespecifically, based on light reception results from light receivingportion 62, detecting device 60 can detects liquid LQ that leaks fromgap G, drops, and passes through space H. Further, based on lightreception results from light receiving portion 64, detecting device 60can detect whether there is liquid LQ on upper surface BT of base memberBP.

Light projecting portion 61 and light receiving portion 62 face eachother, detecting light La emitted from light projecting portion 61reaches light receiving portion 62; and it is configured such thatdetecting light La is received by light receiving portion 62 at apredetermined level of light amount (fight intensity). In this regard,when, as shown in, e.g., FIG. 5, liquid LQ having leaked from gap Gdrops and passes through the optical path of detecting light La,detecting light La is refracted, scattered, or absorbed by liquid LQ.Accordingly, when there is liquid LQ on the optical path of detectinglight La, the light amount (light intensity) received by light receivingportion 62 decreases, or detecting light La does not reach lightreceiving portion 62. Thus, based on the light reception results(light-reception amount) from light receiving portion 62, detectingdevice 60 can detect whether there is liquid LQ on the optical path ofdetecting light La. And thus, by detecting whether there is liquid LQ onthe optical path of detecting light La, detecting device 60 can detectwhether liquid LQ has leaked from gap G.

Similarly, light projecting portion 63 and light receiving portion 64face each other; detecting light Lb emitted from light projectingportion 63 reaches light receiving portion 64; and it is configured suchthat detecting light Lb is received by light receiving portion 64 at apredetermined level of light amount (light intensity). In this regard,if, as shown in FIG. 5, when liquid LQ having leaked is disposed onupper surface BT of base member BP, detecting light Lb illuminatesliquid LQ, then detecting light Lb is refracted, scattered, or absorbedby liquid LQ. Accordingly, based on the light reception results(light-reception amount) from light receiving portion 64, detectingdevice 60 can detect whether there is liquid LQ on the optical path ofdetecting light Lb and thus can detect whether there is liquid LQ onupper surface BT of base member BP.

Each of detecting lights La and detecting lights Lb proceeds side byside along the X-axis-direction. Thus, detecting device 60 can detectleakage of liquid LQ over a wide range of space H and base member BP.Further, when controller CONT judges based on the detection results fromdetecting device 60 that liquid LQ has leaked, controller CONT, forexample, decreases the per-unit-time liquid supply amount by liquidsupply mechanism 10 or stops supplying liquid LQ by liquid supplymechanism 10. Alternatively, based on the detection results fromdetecting device 60, controller CONT increases the per-unit-time liquidrecovery amount by liquid recovery mechanism 20. Alternatively, based onthe detection results from detecting device 60, controller CONT stopsthe exposure operation on substrate P or the movement of the stages ST1and ST2. In this way, when leakage of liquid LQ is detected, controllerCONT can, by taking an appropriate action, prevent liquid LQ fromflowing out onto, e.g., the floor on which exposure apparatus EX,spreading the damage. Additionally, gas bearings 41 and 42 provide withgas suction ports. When there is liquid LQ on base member BP, liquid LQmay flow into the gas suction ports of gas be 41 and 42. Thus, whencontroller CONT judges based on the light reception results from lightreceiving portion 64 that there is liquid LQ on base member BP,controller CONT may stop the sucking operation through gas suction portsof gas bearings 41 and 42. Further, by setting the optical path ofdetecting light Lb to be located near gas bearings 41 and 42, liquid LQcan be detected by using detecting light Lb before liquid LQ on basemember BP flows into gas suction ports of gas bearings 41 and 42; thus,by taking an appropriate action depending on the detection results, itcan be precluded that liquid LQ having flowed out onto base member BPflows into gas suction ports of gas bearings 41 and 42. Further, whenliquid LQ penetrates between the undersurfaces (bearing surfaces) of gasbeatings 41 and 42 and upper surface BT of base member BP, theZ-direction positions of the stages ST1 and ST2 may vary due to theliquid LQ. However, an appropriate action can be taken based on thedetection results from detecting device 60. Further, when controllerCONT judges based on the detection results from detecting device 60 thatliquid LQ has leaked, controller CONT may raise an alarm by operating analarm device, not shown. Since, by this, an operator, for example, canrecognize that liquid LQ has leaked, he or she can take an appropriateaction. The alarm device may raise an alarm by using a warning light, awarning sound, a display, or the like.

Since, in the embodiment, it is configured such that detecting device 60optically detects liquid LQ in a non-contact manner, there is no need todispose wirings or various kinds of devices in the vicinity of, e.g.,base member BP or driving mechanism SD. Thus, the amount of influence onthe movements of the stages ST1 and ST2 can be reduced.

Second Embodiment

FIG. 6 is a drawing showing a second embodiment. In the followingdescription, with respect to the same or equivalent constituent elementsas those in the above-described embodiment, their descriptions will beabridged or omitted. Detecting device 60′ shown in FIG. 6 has both of afunction of a light projecting portion emitting detecting light La′ anda function of a light receiving portion receiving the light. Detectingdevice 60′ is provided on overhang portion H2 of measurement stage ST2.On the other hand, reflecting member 66 having reflecting surface 65 isprovided on a position that is located on overhang portion H1 ofsubstrate stage ST1 and faces detecting device 60′. Detecting device 60′illuminates reflecting surface 65 with detecting light La, receives, atthe same time, the reflected light from reflecting surface 65, anddetects, based upon the light reception results, whether liquid LQ hasleaked from gap G. When liquid LQ does not exist on the optical path ofdetecting light La′, the reflected light of detecting light La′ emittedfrom detecting device 60′ is received by detecting device 60′ at apredetermined level of light intensity. In contrast, since when liquidLQ exists on the optical path of detecting light La′, detecting lightLa′ is scattered or absorbed by liquid LQ, the reflected light thereofis received by detecting device 60′ at a level of light intensity lowerthan the above-mentioned predetermined level of light intensity. Basedupon the light reception results of the reflected light, detectingdevice 60′ can detect whether there is liquid LQ on the optical path ofdetecting light La′ and, thus, whether liquid LQ has leaked. Withreflecting surface 65 being provided, the received light intensitydifference between the case when liquid LQ exists on the optical path ofdetecting light La′ and the case when liquid LQ does not exist thereonbecomes large; thus, detecting device 60′ can detect with high accuracywhether there is liquid LQ on the optical path of detecting light La′.

In addition, in this embodiment, the optical path of detecting light La′emitted from detecting device 60′ exists within gap G between uppersurface F1 and upper surface F2. By adopting such configuration, liquidLQ having leaked into gap G can be immediately detected by usingdetecting light La′.

It should be noted that it may also be configured such that detectingdevice 60′ having both functions of a light projecting portion and alight receiving portion is provided on first side surface T1 (secondside surface T2) that has been described referring to FIG. 5, andreflecting member 66 is provided on second side surface T2 (first sidesurface T1). Similarly, it may also be configured such that detectingdevice 60′ is provided on gas bearing 41 (as bearing 42) that has beendescribed referring to FIG. 5, and reflecting member 66 is provided ongas bearing 42 (gas bearing 41). Conversely, it may also be configuredsuch that light projecting portion 61 that has been described referringto FIG. 5 is provided on overhang portion H1 (or H2), and lightreceiving portion 62 is provided on overhang portion H2 (or H1).

Third Embodiment

FIG. 7 is a drawing exposure apparatus EX′ in accordance with a thirdembodiment. Exposure apparatus EX′ shown in FIG. 7 is such a so-calledtwin-stage type exposure apparatus as disclosed in, e.g., JapaneseUnexamined Patent Publication Hei 10-163099, Japanese Unexamined PatentPublication Hei 10-214783, and Published Japanese Transition2000-505958, in which two substrate stages ST1′ and ST2′ that aremovable while holding a substrate are provided. Also in exposureapparatus EX′ shown in FIG. 7, liquid immersion region LR can be movedbetween upper surface F1′ of first sure stage ST1′ and upper surface F2′of second substrate stage ST2′. Further, by providing detecting device60 (60′) as in the case of the above-described embodiments, liquid LQhaving leaked from between first substrate stage ST1′ and secondsubstrate stage ST2′ when moving liquid immersion region LR from thesurface of one of the stages of first substrate stage ST1′ and secondsubstrate stage ST2′ to the upper surface of the other stage can bedetected.

As described above, in the embodiments, liquid LQ is purified water.Purified water has the advantage that it is easily available in bulk in,e.g, semiconductor manufacturing factories and also the advantage thatit does not adversely affect photoresist on substrate P, opticalelements (lenses), etc. Further, purified water does not adverselyaffect the environment and contains scarcely any impurities; thus, theeffect that it cleans the surface of substrate P and the surface of theoptical element provided at the end portion of projection optical systemPL can be expected. It should be noted that when the purity of thepurified water supplied from, e.g., the factory, it may be configuredsuch that the exposure apparatus itself has an ultrapure water system.

The refractive index n of purified water (water) relative to exposurelight EL having a wavelength of about 193 mm is said to be approximately1.44, and when ArF excimer laser light (having 193 nm wavelength) isused as the light source of exposure light EL, the wavelength iseffectively shortened, on substrate P, as if multiplied by 1/n, i.e.,effectively becomes approximately 134 mn, and thus, a high resolutioncan be obtained. Further, since the depth of focus increases byapproximately n times, i.e., approximately by 1.44 times, compared withthat in the air, when securing of the depth of focus on par with thedepth of focus realized when the projection optical system is used inthe air suffices, the numerical aperture of the projection opticalsystem PL can be further increases which also improves the resolution.

It should be noted that while, in the embodiments, liquid LQ is water(purified water), liquid LQ may be a liquid other than was For example,when the light source of exposure light EL is an F₂ laser, the F₂ laserlight does not transmit through water, and thus, as liquid LQ, afluorofluid that can transit the F₂ laser light, such asperfluorcpolyether (PFPE) or fluorochemical oil, may be used. In thiscase, the portions that come into contact with liquid LQ are appliedwith lyophilic treatment, by forming a thin film of a substance whichincludes, e.g., fluorine and has a molecular structure of a smallpolarity. Further, as liquid LQ, a material (e.g., cedar oil) that cantransmit exposure light EL, has a high refractive index as high aspracticable, and does not affect projection optical system PL and thephotoresist applied to the surface of substrate P can also be used. Alsoin this case, the surface treatment is applied in accordance with thepolarity of liquid LQ to be used.

Further, while the exposure apparatus, to which the above-describedimmersion liquid method is applied, is configured such that with theoptical path space on the exit side of fit optical element LS1 ofprojection optical system PL being filled with a liquid (purifiedwater), substrate P is exposed, the optical path space on the incidenceside of firs optical element LS1 of projection optical system PL mayalso be filled with the liquid (purified water), as disclosed in theInternational Publication WO 2004/019128.

It is to be noted that regarding substrate P of each of the abovedescribed embodiments, not only a semiconductor wafer for many asemiconductor device, but also a glass for a display device, a ceramicwafer for a thin film magnetic head, a master mask or reticle (syntheticquartz or silicon wafer), etc. can be used.

Regarding exposure apparatus EX, in addition to a scan type exposureapparatus (scanning stepper) in which while synchronously moving mask Mand substrate P, the patter of mask M is scan-exposed, a step-and-repeattype projection exposure apparatus (stepper) in which the pattern ofmask M is exposed at one time in the condition that mask M and substrateP are stationary, and substrate P is successively moved stepwise can beused.

Further, regaining exposure apparatus EX, the present invention can beapplied to an exposure apparatus in which in the state that a firstpattern and substrate P are substantially stationary, the reductionimage of the first pattern is exposed at one time by using a projectionoptical system (e.g., a refraction type projection optical system thathas a reduction magnification of ⅛ and includes no reflecting element).In this case, the present invention can be applied to a stitch typeone-shot exposure apparatus in which thereafter, in the state that asecond pattern and substrate P are substantially stationary, thereduction image of the second pattern is exposed at one time ontosubstage P by using the projection optical system in a manner that thefirst pattern image and the second pattern image partially overlap witheach other. Further, in conjunction with the stitch, type exposureapparatus, the present invention can also be applied to a step andstitch type exposure apparatus in which at least two patterns aretransferred onto substrate P in a partially overlapping manner, andsubstrate P is successively moved.

In the above-described embodiments, a light transmission type mask onwhich a predetermined light-shielding pattern (or a phase pattern/lightdecreasing pattern) is formed on a light transmissive substrate is used,however, instead of such mask, an electronic mask that forms, based uponthe electronic data of a pattern to be exposed, a transmission pattern,a reflection pattern, or a light emitting pattern may also be used, asdisclosed in, e.g., U.S. Pat. No. 6,778,257.

Further, the present invention can be applied also to an exposureapparatus (lithography system) in which by forming interference fringeson substrate P, a line-and-space pattern is exposed onto substrate P, asdisclosed in the International Publication WO 2001/035168 pamphlet.

Further, while, in the above-described embodiments, the exposureapparatus, in which the liquid locally fills the space betweenprojection optical system PL and substrate P, is adopted, the presentinvention can also be applied to a liquid immersion exposure apparatusin which the entire surface of a substrate to be exposed is covered by aliquid. The structure and exposure operation of an exposure apparatus inwhich the entire surface of a subdue to be exposed is covered by aliquid are described in, e.g., Japanese Unexamined Patent PublicationHei 6-124873, Japanese Unexamined Patent Publication Hei 10-303114, orU.S. Pat. No. 5,825,043.

Regarding the type of expo apparatus EX, the present invention is notlimited to an exposure apparatus, which exposes a semiconductor patternonto substrate P, for manufacturing semiconductor devices, however canalso be applied to a variety of exposure apparatuses, e.g., an exposureapparatus for manufacturing liquid crystal display devices or adisplays, an exposure apparatus for manufacturing thin film magneticheads, an exposure apparatus for manufacturing image pickup devices(CCDs), and an exposure apparatus for manufacturing reticles or masks.

Exposure apparatus EX according to the embodiments of the presentapplication is built by assembling various subsystems, including eachelement listed in the claims of the present application, in such amanner that prescribed mechanical accuracy, electrical accuracy, andoptical accuracy are maintained. In order to ensure the variousaccuracies, prior to and after the assembly, every optical system isadjusted to achieve its optical accuracy, every mechanical system isadjusted to achieve its mechanical accuracy, and every electrical systemis adjusted to achieve its electrical accuracy. The process ofassembling each subsystem into the exposure apparatus includesmechanical interfaces, electrical circuit wiring connections, and airpressure plumbing connections between each subsystem. Needless to say,there is also a process where each subsystem is assembled prior to theassembling of the exposure apparatus from the various spasms. Oncompletion of the process of assembling the various subsystems in theexposure apparat, overall adjustment is performed to make sure thatevery accuracy is maintained in the complete exposure apparatus.Additionally, it is desirable to manufacture the exposure apparatus in aclean room, in which the temperature, purity, etc. are controlled.

As shown in FIG. 8, micro devices such as semiconductor devices aremanufactured by a series of steps, including: step 201 in which themicro device's function and performance design is performed; step 202 inwhich a mask (reticle) is mama based on the design step; step 203 inwhich a substrate, the device's base material, is manufactured;substrate processing step 204 including a process in which the maskpattern is exposed onto the substrate by exposure apparatus EX accordingto the above-described embodiments; device assembly step 205 (includinga dicing process, a bonding process, and a packaging process);inspection step 206.

1. An exposure apparatus that exposes a substrate via a projectionoptical system, comprising: a first stage and a second stage that aremovable, on an image plane side of the projection optical system,independently of each other in a two-dimensional plane substantiallyparallel to the image plane, a driving system that moves the first stageand the second stage together within a predetermined region including aposition directly beneath the projection optical system with the firststage and the second stage being close to or in contact with each other,a liquid immersion system that forms a liquid immersion region of aliquid on an upper surface of at least one of the stages of the firstand second stages, a controller that, by moving the first and secondstages together, moves the liquid immersion region between the uppersurface of the first stage and the upper surface of the second stagewith the liquid being retained between the projection optical system andthe upper surface of the at least one of the stages, and a detectingdevice that detects the liquid having leaked from between the first andsecond stages when the liquid immersion region is moved from the uppersurface of one of the stages of the first and second stages to the uppersurface of the other stage of the first and second stages.
 2. Theexposure apparatus according to claim 1, wherein the detecting devicedetects the liquid in a non-contact manner.
 3. The exposure apparatusaccording to claim 1, wherein the detecting device includes a lightprojecting portion that emits a detecting light and a light receivingportion which is disposed in a predetermined position relative to thedetecting light.
 4. The exposure apparatus according to claim 3, whereinthe second stage has a second side surface that faces a first sidesurface of the first stage, and the light projecting portion is providedon either one of the first side surface and the second side surface, andthe light receiving portion is provided on the other of the first sidesurface and the second side surface.
 5. The exposure apparatus accordingto claim 3, further comprising a base member that movably supports eachof the first and second stages, and wherein the detecting light proceedsin a vicinity of the base member.
 6. The exposure apparatus according toclaim 5, further comprising gas bearings that are provided on the firstand second stages, respectively, and support in a non-contact manner thefirst and second stages relative to an upper surface of the base member,and wherein the light projecting portion and the light receiving portionare provided adjacent to the gas bearings.
 7. The exposure apparatusaccording to claim 1, wherein one of the stages of the first and secondstages moves while holding the substrate, and the other stage of thefirst and second stages moves, with a measuring device that performs ameasurement related to the exposure process being mounted on the otherstage.
 8. The exposure apparatus according to claim 1, wherein each ofthe first and second stages moves while holding a substrate.
 9. Theexposure apparatus according to claim 1, wherein the liquid immersionsystem stops supplying the liquid when leakage of the liquid isdetected.
 10. The exposure apparatus according to claim 9, wherein theliquid immersion system continues recovering the liquid which forms theliquid immersion region when leakage of the liquid is detected by thedetecting device.
 11. A device manufacturing method comprising: loadinga substrate on one of the first and second stages of the exposureapparatus according to claim 1; and projecting an image of a patternonto the substrate held by the one stage.
 12. The exposure apparatusaccording to claim 7, wherein the other stage has no substrate holderfor holding a substrate.
 13. A control method of an immersionlithography apparatus that exposes a pattern image onto a substrate viaa projection optical system and an immersion liquid supplied between theprojection optical system and an upper surface of the substrate, theimmersion lithography apparatus including a first stage and a secondstage that are movable, on an image plane side of the projection opticalsystem, independently of each other in a two-dimensional planesubstantially parallel to the image plane, the method comprising: movingthe first and second stages together within a predetermined regionincluding a position directly beneath the projection optical system withthe first and second stages being close to or in contact with eachother, forming a liquid immersion region of the immersion liquid on anupper surface of at least one of the stages of the first and secondstages, moving the first and second stages together so as to move theliquid immersion region between the upper surface of the first stage andthe upper surface of the second stage with the immersion liquid beingretained between the projection optical system and the upper surface ofthe at least one of the stages, and detecting whether the immersionliquid has leaked from between the first and second stages when theliquid immersion region is moved from the upper surface of one of thestages of the first and second stages to the upper surface of the otherstage of the first and second stages.
 14. The method according to claim13, wherein the detecting is performed by a detecting device thatdetects the liquid in a non-contact manner.
 15. The method according toclaim 13, wherein the detecting is performed by emitting a detectinglight from a light projecting portion and by receiving the detectinglight with a light receiving portion which is disposed in apredetermined position relative to the detecting light.
 16. The methodaccording to claim 15, wherein: the second stage has a second sidesurface that faces a first side surface of the first stage, and thelight projecting portion is provided on either one of the first sidesurface and the second side surface, and the light receiving portion isprovided on the other of the first side surface and the second sidesurface.
 17. The method according to claim 15, wherein the immersionlithography apparatus includes a base member that movably supports eachof the first and second stages, and wherein the detecting light proceedsin a vicinity of the base member.
 18. The method according to claim 17,wherein the immersion lithography apparatus includes gas bearings thatare provided on the first and second stages, respectively, and supportin a non-contact manner the first and second stages relative to an uppersurface of the base member, and wherein the light projecting portion andthe light receiving portion are provided on the gas bearings.
 19. Themethod according to claim 13, further comprising moving one of thestages of the first and second stages while holding the substrate, andmoving the other stage of the first and second stages, with a measuringdevice that performs a measurement related to the exposure process beingmounted on the other stage.
 20. The method according to claim 13,further comprising moving each of the first and second stages whileholding a substrate.
 21. The method according to claim 13, furthercomprising stopping a supplying of the liquid to the immersion regionwhen leakage of the liquid is detected.
 22. The method according toclaim 21, further comprising recovering the liquid which forms theliquid immersion region when leakage of the liquid is detected.
 23. Adevice manufacturing method comprising: loading a substrate on one offirst and second stages of the immersion lithography apparatuscontrolled according to claim 13; and projecting an image of a patternonto the substrate held by the one stage.